1. Field of the Invention
The invention pertains to wire dispensers for dispensing and uncoiling wire from a spool having end flanges wherein the dispenser base is mounted within a coaxial hole in an end flange and the dispensed wire is guided through a rotating arm mounted upon the base.
2. Description of the Related Art
Arc welders are often supplied by welding wire from a wire coil wound upon a spool. The length of the spool is defined by spool end flanges having a central hole, and during wire dispensing, the spool axis is vertically oriented wherein the lower spool flange constitutes the spool support, and a wire dispenser is mounted upon the upper spool flange.
Welding wire dispensers often include rotating arms having wire guides or tubes supported upon a base mounted upon the spool or spool pallet and the arm may include a friction brake to control the rate of arm rotation about the spool as the wire is guided through the rotating arm. Wire dispensers of this general type are shown in U.S. Pat. Nos. 1,834,159; 2,319,828; 2,880,305; 3,618,873; 4,253,624 and 4,657,204.
In common practice, welding wire is shipped and sold on spools having wood or composite end flanges. The end flanges are provided with a hole coaxial with the spool axis which is of a circular configuration and may be three or four inches in diameter, large enough to receive the base of a rotating arm dispenser. The dispenser base is received within the upper spool flange hole, and includes coaxial bearing structure supporting the rotating arm and the rotating arm and base usually include a friction brake device for imposing a resistance to arm rotation to prevent the arm from over travel as the wire is intermittently pulled through the arm to insure a uniform dispensing of the wire through the rotating arm.
The dispenser base is held in the spool circular hole by friction and the circular base must fit snugly within the spool flange hole to prevent relative rotation between the base and the spool flange. Due to the torque imposed on the base by its friction brake, it is a common problem for the dispenser to rotate within the spool hole when the frictional engagement between the dispenser base and spool hole reduces to the point where the flange hole is no longer able to firmly and snugly support the dispenser base and inadequate support of the rotating arm occurs, and relative rotation between the base and spool flange results in improper arm rotation adversely affecting the dispensing of the wire from the spool.
Another problem which occurs with welding wire dispensers of the rotating arm type results from the wear occurring within the arm tube as many thousands of feet of wire will be pulled through the dispenser arm throughout its operating life, and the curved configuration of the arm produces high wear points such that the metal arm tube will be worn through by the movement of the welding wire therein.